San Ramon, CA Outdoor Lighting: Light Trespass (2026)

Glare and light spillover are addressed in the San Ramon Development Code performance standards and lighting chapter. Typical standards: illumination measured horizontally at residential property lines may not exceed 0.5 foot-candles (some districts 1.0 fc for non-residential); fixtures visible from residential properties must be full-cutoff design (no light emitted above the horizontal plane of the fixture); high-intensity sources (floodlights, halogen work lights) cannot be aimed toward neighbors or the public right-of-way; photometric plans with iso-footcandle diagrams are required for commercial projects and large residential developments. Common residential issues include: dusk-to-dawn security lights aimed at neighbors, landscape up-lighting spilling skyward, sports court lighting for home tennis/basketball courts, pool area floodlights, and holiday lights left on permanently or flashing/animated. Code enforcement typically responds to complaints with a site inspection at night to measure glare/spillover; owners are asked to reaim, shield, or replace fixtures. Persistent violations result in administrative citations. California Civil Code does not directly address light nuisance, but courts have recognized excessive light as a private nuisance under Civil Code 3479 when it unreasonably interferes with use and enjoyment of neighboring property. Commercial and industrial properties near residential zones have stricter transitional lighting standards. Sign lighting (see signage chapter) has its own standards. Proper fixture selection — BUG (Backlight, Uplight, Glare) ratings B1/U0/G1 or better — generally avoids code issues.